Dendritic Cell Immunoreceptor: A Novel Receptor for Intravenous Immunoglobulin Mediates Induction of Regulatory T Cells

J Allergy Clin Immunol. 2014 Mar;133(3):853-63.e5. doi: 10.1016/j.jaci.2013.09.029. Epub 2013 Nov 8.

Abstract

Background: Intravenous immunoglobulin (IVIg) is a polyclonal IgG preparation with potent immunomodulating properties. Our laboratory demonstrated that IVIg significantly increases numbers of forkhead box protein 3-positive regulatory T (Treg) cells through generation of tolerogenic dendritic cells (DCs) in an allergic airways disease model.

Objective: We sought to investigate potential receptors on DCs mediating these events.

Methods: C57BL/6 mice were either sensitized to ovalbumin (OVA) intraperitoneally or through adoptive transfer of OVA-primed DCs and then challenged with intranasal OVA. IVIg was fractionated into sialic acid-enriched IVIg (SA-IVIg) and sialic acid-depleted IVIg (non-SA-IVIg). Dendritic cell immunoreceptor (DCIR) constructs in CHO cells or on DCs were examined by using fluorescent microscopy and flow cytometry.

Results: Administration of SA-IVIg, but not non-SA-IVIg, to OVA-sensitized and OVA-challenged mice induced Treg cells and attenuated airway hyperresponsiveness (AHR) and inflammation comparably with IVIg. Bone marrow-derived dendritic cells cultured with SA-IVIg or IVIg adoptively transferred to mice before OVA challenge induced Treg cells and inhibited AHR. IVIg-treated bone marrow-derived dendritic cells from Fcγ receptor knockout mice inhibited AHR, suggesting IVIg's action was not caused by Fcγ receptor-mediated events. Fluorescently labeled IVIg or SA-IVIg bound DCs and colocalized specifically to the C-type lectin DCIR. IVIg binding to DCIR induced phosphorylation of Src homology domain 2-containing protein tyrosine phosphatase (SHP) 2 and Src homology domain 2-containing inositol phosphatase 1 (SHIP-1) and internalization of IVIg into DCs. Inhibition of IVIg binding to DCIR by small interfering RNA completely blocked induction of Treg cells. Inhibition of SHP-2 or abrogation of IgG internalization through clatherin inhibitors rendered IVIg ineffective.

Conclusions: IVIg alleviates allergic airways disease through interaction of SA-IgG with DCIR. DCIR is a novel receptor for IVIg, mediating interaction of innate and adaptive immunity in tolerogenic responses.

Keywords: Intravenous immunoglobulin; asthma; dendritic cells; immune modulation; regulatory T cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bronchial Hyperreactivity / prevention & control
  • CHO Cells
  • Cricetulus
  • Dendritic Cells / immunology
  • Immunoglobulin G / immunology
  • Immunoglobulins, Intravenous / pharmacology*
  • Inositol Polyphosphate 5-Phosphatases
  • Lectins, C-Type / physiology*
  • Membrane Glycoproteins / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Ovalbumin / immunology
  • Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases
  • Phosphoric Monoester Hydrolases / metabolism
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11 / metabolism
  • Receptors, Immunologic / physiology*
  • T-Lymphocytes, Regulatory / immunology*

Substances

  • CLEC4A protein, human
  • Immunoglobulin G
  • Immunoglobulins, Intravenous
  • Lectins, C-Type
  • Membrane Glycoproteins
  • Receptors, Immunologic
  • Ovalbumin
  • Phosphoric Monoester Hydrolases
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Inositol Polyphosphate 5-Phosphatases
  • INPP5D protein, human
  • Inpp5d protein, mouse
  • Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases